Production of pyrroloquinazoline alkaloid from leaf and petiole-derived callus cultures of Adhatoda zeylanica

Callus cultures of Adhatoda zeylanica Medicus were established from leaf and petiole explants. Accumulation of a bioactive pyrroloquinazoline alkaloid, vasicine, in callus cultures was detected and confirmed by thin layer chromatography, electron-ionization mass spectra, C-13 NMR and high-pressure liquid chromatography analysis. The mass of vasicine obtained from leaf-derived callus cultures was found as 188 and this is comparable to that of the authentic sample. The retention time for leaf-derived extract was 10.065 and for the petiole-derived extract was 9.78 (authentic sample had 9.6 retention time) on high-performance liquid chromatography. The mass and NMR spectra were compared with the spectra obtained from the authentic sample of vasicine. Different growth regulators greatly influenced the growth of callus cultures. The accumulation of vasicine was more in leaf-derived callus grown on Murashige and Skoog (MS) medium fortified with 10.7 mu M naphthaleneacetic acid (NAA) and 4.4 mu M 6-benzyladenine than in petiolar callus grown on MS medium with 2.3 mu M kinetin, and 4.5 mu M 2,4-dichlorophenoxyacetic acid. This is the first report on in vitro production of a pharmacologically important compound vasicine and its characterization by mass spectrometry and C-13 NMR studies from callus cultures of Adhatoda zeylanica.